Are Ethnic and Gender Specific Equations Needed to Derive Fat Free Mass from Bioelectrical Impedance in Children of South Asian, Black African-Caribbean and White European Origin? Results of the Assessment of Body Composition in Children Study

Background Bioelectrical impedance analysis (BIA) is a potentially valuable method for assessing lean mass and body fat levels in children from different ethnic groups. We examined the need for ethnic- and gender-specific equations for estimating fat free mass (FFM) from BIA in children from different ethnic groups and examined their effects on the assessment of ethnic differences in body fat. Methods Cross-sectional study of children aged 8–10 years in London Primary schools including 325 South Asians, 250 black African-Caribbeans and 289 white Europeans with measurements of height, weight and arm-leg impedance (Z; Bodystat 1500). Total body water was estimated from deuterium dilution and converted to FFM. Multilevel models were used to derive three types of equation {A: FFM = linear combination(height+weight+Z); B: FFM = linear combination(height2/Z); C: FFM = linear combination(height2/Z+weight)}. Results Ethnicity and gender were important predictors of FFM and improved model fit in all equations. The models of best fit were ethnicity and gender specific versions of equation A, followed by equation C; these provided accurate assessments of ethnic differences in FFM and FM. In contrast, the use of generic equations led to underestimation of both the negative South Asian-white European FFM difference and the positive black African-Caribbean-white European FFM difference (by 0.53 kg and by 0.73 kg respectively for equation A). The use of generic equations underestimated the positive South Asian-white European difference in fat mass (FM) and overestimated the positive black African-Caribbean-white European difference in FM (by 4.7% and 10.1% respectively for equation A). Consistent results were observed when the equations were applied to a large external data set. Conclusions Ethnic- and gender-specific equations for predicting FFM from BIA provide better estimates of ethnic differences in FFM and FM in children, while generic equations can misrepresent these ethnic differences

A Mediterranean-like dietary pattern with vitamin D3 (10 µg/d) supplements reduced the rate of bone loss in older Europeans with osteoporosis at baseline: results of a 1-y randomized controlled trial

Background: The Mediterranean diet (MD) is widely recommended for the prevention of chronic disease, but evidence for a beneficial effect on bone health is lacking.  Objective: The aim of this study was to examine the effect of a Mediterranean-like dietary pattern [NU-AGE (New Dietary Strategies Addressing the Specific Needs of the Elderly Population for Healthy Aging in Europe)] on indexes of inflammation with a number of secondary endpoints, including bone mineral density (BMD) and biomarkers of bone and collagen degradation in a 1-y multicenter randomized controlled trial (RCT; NU-AGE) in elderly Europeans.  Design: An RCT was undertaken across 5 European centers. Subjects in the intervention group consumed the NU-AGE diet for 1 y by receiving individually tailored dietary advice, coupled with supplies of foods including whole-grain pasta, olive oil, and a vitamin D3 supplement (10 µg/d). Participants in the control group were provided with leaflets on healthy eating available in their country.  Results: A total of 1294 participants (mean ± SD age: 70.9 ±4.0 y; 44% male) were recruited to the study and 1142 completed the 1-y trial. The Mediterranean-like dietary pattern had no effect on BMD (site-specific or whole-body); the inclusion of compliance to the intervention in the statistical model did not change the findings. There was also no effect of the intervention on the urinary biomarkers free pyridinoline or free deoxypyridinoline. Serum 25-hydroxyvitamin D significantly increased and parathyroid hormone decreased (P < 0.001) in the MD compared with the control group. Subgroup analysis of individuals with osteoporosis at baseline (site-specific BMD T-score ≤ −2.5 SDs) showed that the MD attenuated the expected decline in femoral neck BMD (n = 24 and 30 in MD and control groups, respectively; P = 0.04) but had no effect on lumbar spine or whole-body BMD.  Conclusions: A 1-y intervention of the Mediterranean-like diet together with vitamin D3 supplements (10 µg/d) had no effect on BMD in the normal age-related range, but it significantly reduced the rate of loss of bone at the femoral neck in individuals with osteoporosis. The NU-AGE trial is registered at clinicaltrials.gov as NCT01754012

A combined DHA-rich fish oil and cocoa flavanols intervention does not improve cognition or brain structure in older adults with memory complaints: Results from the CANN randomized, controlled parallel-design study

Background There is evidence that both omega-3 long-chain PUFAs (EPA and DHA) and cocoa flavanols can improve cognitive performance in both healthy individuals and in those with memory complaints. However, their combined effect is unknown. Objective To investigate the combined effect of EPA/DHA and cocoa flavanols (OM3FLAV) on cognitive performance and brain structures in older adults with memory complaints. Methods A randomized placebo-controlled trial of DHA-rich fish oil (providing 1.1 g/d DHA and 0.4 g/d EPA) and a flavanol-rich dark chocolate (providing 500 mg/d flavan-3-ols) was conducted in 259 older adults with either Subjective Cognitive Impairment (SCI) or Mild Cognitive Impairment (MCI). Participants underwent assessment at baseline, 3 and 12 months. The primary outcome was number of false positives on a picture recognition task from the Cognitive Drug Research (CDR) computerized assessment battery. Secondary outcomes included other cognition and mood outcomes, plasma lipids, brain derived neurotrophic factor (BDNF) and glucose levels. A subset of 110 participants underwent structural neuroimaging at baseline and at 12-months. Results 197 participants completed the study. The combined intervention had no significant effect on any cognitive outcomes, with the exception of reaction time variability (p=0.007), alertness (p<0.001) and executive function (p<0.001), with a decline in function observed in the OM3FLAV group (118.6 (25.3) at baseline versus 113.3 (25.4) at 12m for executive function) relative to the control, and an associated decrease in cortical volume (p=0.039). Compared with the control group, OM3FLAV increased plasma HDL-cholesterol, total-cholesterol ratio (p<0.001) and glucose (p=0.008) and reduced TG concentrations (p<0.001) by 3m which were sustained to 12m, with no effect on BDNF. Changes in plasma EPA and DHA and urinary flavonoid metabolite concentrations confirmed compliance to the intervention. Conclusions These results suggest that co-supplementation with omega-3 PUFA and cocoa flavanols for 12 months does not improve cognitive outcomes in those with cognitive impairment

Bland-Altman plots for equations for deriving fat free mass from bioelectrical impedance analysis in ABCC Study by ethnicity.

<p>Equation A1, fat free mass = height+weight+Z (generic model); Equation A4, fat free mass = height+weight+Z (ethnic- and gender-specific model); Equation C1, fat free mass = height²/Z+weight (generic model); Equation C4, fat free mass = height²/Z+weight (ethnic- and gender-specific model). Abbreviations: FFM, fat free mass; WE, white European; BAC, black African-Caribbean; SA, South Asian; Z, impedance.</p

Coefficients from regression models deriving equations for estimating fat free mass by fitting height, weight and impedance as separate variables in the model and adding interaction terms for ethnicity and gender.

<p>Abbreviations: CI, confidence interval; BAC, Black African-Caribbean; SA, South Asian; HT, height; WT, weight; Z, impedance.</p><p>All models are adjusted for random effect of school.</p

Comparison of ethnic differences in body composition using different equations for deriving fat free mass in CHASE data.

*<p>Percentage differences shown for log transformed variables.</p><p>Abbreviations: CI, confidence interval; HT, height; WT, weight; Z, impedance.</p><p>Adjusted for gender, age quartiles, observer (skinfolds only) and a random effect for school.</p

Coefficients from regression models deriving equations for estimating fat free mass by fitting height²/impedance and weight as variables in the model and adding interaction terms for ethnicity and gender.

<p>Abbreviations: CI, confidence interval; BAC, Black African-Caribbean; SA, South Asian; HT²/Z, height²/impedance; WT, weight.</p><p>All models are adjusted for random effect of school.</p

An Experiment in Using Visual Attention Metrics to Think About Experience and Design Choices in Past Places

The influence of the visual properties of a built space or landscape on the behaviors of people within them and the manipulation of these visual properties to cue or constrain behaviors are subjects of long-standing archaeological interest. Advances in cognitive neurosciences and a suite of improved computational modeling tools, combined with the proliferation of detailed 3D models of archaeological complexes and landscapes, offer an opportunity for new approaches to these topics based on models of low-level perceptual cues and visual attention. The approach described here takes aim at the question of where people will look, rather than simply what is visible, with the goal of investigating the intentions of designers of spaces and visual aspects of the experience of a place. In simple terms, our approach involves placing detailed 3D models of built spaces or landscapes into a digital environment. An individual then virtually walks through the space and what is visible at each moment is recorded in the form of a video stream, which may be broken down into a sequence of scenes. This set of scenes is then analyzed using software that calculates and maps the visual saliency of each scene and the path of focuses of attention (FOAs) over time. This set of saliency maps, raw images, and FOA paths provide the basis for further interpretation. This paper presents an initial experiment to illustrate the approach, carried out in the eastern passage at Knowth, one of the main mounds in the Brú na Bóinne in Ireland